Dielectric ceramic composition

Abstract

The present invention provides a dielectric ceramic composition whose electrostatic capacity has an excellently low temperature dependence; which can be fired in a reducing atmosphere; and which is advantageously used in a laminated ceramic capacitor having an internal electrode formed of a base metal such as nickel or nickel alloy. The dielectric ceramic composition is represented by the following formula: {Ba 1−x Ca x O} m TiO 2 +αMgO+βMnO, wherein 0.001≦α≦0.05; 0.001≦β≦0.025; 1.000<m≦1.035; and 0.02≦x≦0.15.

What is claimed is:  
     
       1. A dielectric ceramic composition comprising a complex oxide containing Ba, Ca, Ti, Mg and Mn as metal elements and not having a core-shell structure. 
     
     
       2. A dielectric ceramic composition according to claim  1  represented by 
       
         
           {Ba 1−x−y Ca x RE y O} m TiO 2 +αMgO+βMnO,  
         
       
       wherein RE is a rare earth metal element, 
       
         
           0.001≦α≦0.05; 0.001≦β≦0.025; 1.000<m≦1.035; 0.02≦x≦0.15; and y≦0.06.  
         
       
     
     
       3. A dielectric ceramic composition according to claim  2 , wherein y is 0. 
     
     
       4. A dielectric ceramic composition according to claim  3 , wherein the alkali metal content is less than 0.03 weight percent and the composition is a particulate having an average particle size of 0.1-0.8 μm. 
     
     
       5. A dielectric ceramic composition according to claim  4 , wherein the alkali metal content is less than 0.02 weight percent, the average particle size is about 0.1-0.3 μm and the maximum particle size is about 0.8 μm. 
     
     
       6. A dielectric ceramic composition according to claim  4 , wherein the alkali metal content is less than 0.02 weight percent, the average particle size is about 0.3-0.8 μm and the maximum particle size is about 1 μm. 
     
     
       7. A dielectric ceramic composition according to claim  3 , further comprising a sintering aid in an amount of about 0.2-5.0 parts by weight based on 100 parts by weight of the remaining components of the dielectric ceramic composition. 
     
     
       8. A dielectric ceramic composition according to claim  7 , wherein the sintering aid comprises SiO 2 . 
     
     
       9. A dielectric ceramic composition according to claim  2 , wherein y is at least 0.001. 
     
     
       10. A dielectric ceramic composition according to claim  9 , wherein the alkali metal content is less than 0.03 weight percent and the composition is a particulate having an average particle size of 0.1-0.8 μm. 
     
     
       11. A dielectric ceramic composition according to claim  10 , wherein the alkali metal content is less than 0.02 weight percent, RE is at least one element selected from the group consisting of Y, Gd, Tb, Dy, Ho, Er and Yb, the average particle size is about 0.1-0.3 μm and the maximum particle size is about 0.8 μm. 
     
     
       12. A dielectric ceramic composition according to claim  10 , wherein the alkali metal content is less than 0.02 weight percent, the average particle size is about 0.3-0.8 μm and the maximum particle size is about 1 μm. 
     
     
       13. A dielectric ceramic composition according to claim  9 , further comprising a sintering aid in an amount of about 0.2-5.0 parts by weight based on 100 parts by weight of the remaining components of the dielectric ceramic composition. 
     
     
       14. A dielectric ceramic composition according to claim  13 , wherein the sintering aid comprises SiO 2 . 
     
     
       15. A dielectric composition according to claim  2 , wherein x is at least 0.5. 
     
     
       16. A dielectric composition according to claims  3 , wherein x is at least 0.5. 
     
     
       17. A dielectric composition according to claim  4 , wherein x is at least 0.5.